Study Of Preservative And Fresh-keeping Effect Of Walnut Green Husk Extracts On Firut

Fruits are easily to soften and susceptible to be infected by pathogens at ambienttemperature, resulting in a serious postharvest loss. These diseases are primarily controlled byadding synthetic fungicides. However, chemical fungicides showed negative effects on theenvironment and human health. Lot of new strategies for controlling postharvest diseaseshave been proposed. Natural compounds with antimicrobial activity and eliciting propertiesmight be alternatives to synthetic fungicides in the control of postharvest disease of fruit.Coatings are thin layers of material made from biodegradable ingredients that can beconsumed as a part of the food product and can act as a selective barrier to gas transport.Walnut green husk extracts material was extracted with80%ethanol (EEW),80%methanol, water, and the rough extracts were tested for their inhibitory activity against fruitrot-causing fungi using mycelium growth rate and spore germination rate methods. Highperformance liquid chromatography (HPLC) was used to determine the content of juglone,and the correlation between the content and inhibitory activity. The results showed that80%ethanol extract, with the highest content of juglone, could significantly inhibit the myceliumgrowth and spore germination of Penicillium citrinum, Rhizopus stolonifer, Botryis cinerea,Fusarium oxysporum, Alternaria. The minimum inhibitory concentration (MIC) was alsoassessed, the MIC values of EEW are5.00mg/mL,10.00mg/mL,10.00mg/mL,10.00mg/mL and5.00mg/mL.The preservative and fresh-keeping experiment results of walnut green husk extracts ontomato shows that this extract has obviously fresh-keeping effects. Compared to the controltesting, this preservative liquid can reduce respiratory intensity and retain the firmness of thetomato. The result shows it can reduce the loss of the consumption of nutrients, the rot rate,inhibition of respiration intensity. The result also shows this preservative liquid can enhancethe activity of PPO, POD and PAL.The matching liquor was made of walnut green husk extracts and chitosan, using thisliquid as preservative on muskmelon. The result shows this matching liquid can reduce the decay index of muskmelon and can lower the respiratory intensity of the muskmelon. Theresult also shows this matching liquid can remain the firmness of muskmelon and it cancontrol the consumption of the nutrient of muskmelon.. The best matching preservative liquidon muskmelon storage is CHE-20(including2%chitosan and walnut green husk extracts of40mg/mL such as volume mixing). CHE-20formula suitable melon and fresh pomegranate.